SAA-C03 Design Resilient Architectures Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Use an active/active design with multi-Region data replication (for example, global tables for the write-heavy datastore) and route traffic to multiple Regions based on health and latency.

  Why this is correct

  Active/active with multi-Region replication (such as DynamoDB global tables) allows writes to succeed in multiple AWS Regions simultaneously, ensuring near-zero RPO and immediate write availability during a Regional failure. Routing traffic by health and latency distributes load intelligently and automatically shifts users to the nearest healthy Region, which directly satisfies the global, write-heavy workload's requirement for continuous writes with minimal data loss.

• ✗

  Use warm standby with periodic backups of the primary write datastore every 24 hours.

  Why it's wrong here

  Warm standby with 24-hour backups of the primary write datastore offers recovery but with an RPO of up to 24 hours, because any writes after the last backup are lost. Moreover, restoring a backup and promoting the secondary to primary takes significant time (RTO), so the application would experience a lengthy outage without the ability to accept writes—contradicting the near-zero data loss and continuous write availability requirements.

  When this WOULD be correct

  This option would be correct for a non-critical application that can tolerate up to 24 hours of data loss and does not require write availability during a disaster. For example, a batch processing system where data is not time-sensitive and recovery time objective (RTO) is measured in hours.

• ✗

  Use pilot light where the secondary Region runs only infrastructure templates and starts data replication only after detecting failure.

  Why it's wrong here

  Pilot light keeps the secondary Region dormant and only starts replicating data after a failure is detected, meaning the data store there is stale and cannot serve writes until replication is established. This creates an RPO equal to the time since the last replication and introduces failover latency, so it cannot provide near-zero data loss or permit continued writes during the incident—both of which are mandatory for the global write-heavy application.

  When this WOULD be correct

  A question requiring cost-effective disaster recovery with RPO of hours and RTO of minutes, where the primary region is expected to recover quickly and data loss of a few minutes is acceptable. For example: 'An application needs to recover from a regional failure within 30 minutes and can tolerate up to 1 hour of data loss.'

• ✗

  Use a single-writer model in one Region and deploy read-only replicas in the other Region for continuity.

  Why it's wrong here

  A single-writer model in one Region with read-only replicas elsewhere cannot accept writes in the secondary Region during an outage; the application would either fail or need a manual/automated promotion of the replica to a writable state. That promotion is a failover mechanism with inherent RTO and potential data loss, whereas the stated requirement demands uninterrupted write capability and near-zero data loss during the incident, so this design does not meet the core need.

  When this WOULD be correct

  This option would be correct for a read-heavy application that requires strong consistency and can tolerate brief write interruptions during failover, with the primary goal of minimizing read latency in secondary Regions via read replicas.

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The SAA-C03 exam frequently reuses these exact scenarios with slightly different constraints.

Analysis generated from the official SAA-C03blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”

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